Modular engine family

ABSTRACT

A modular family of internal combustion engines is described. The family includes at least three engine configurations selected from a single cylinder, V-type, inline, opposed, W-type, and radial configurations. Each of the engines in the family includes at least one cylinder with identical top end packages. A method for designing such a family of engines is also disclosed. A family of recreational vehicles and method for designing a family of recreational vehicles is also disclosed.

[0001] The present application relies for priority on U.S. ProvisionalPatent Application Ser. No. 60/234,966, entitled “Modular EngineFamily,” filed on Sep. 25, 2000, which is incorporated herein byreference.

[0002] This application also incorporates herein by reference U.S.Provisional Patent Application Ser. No. 60/185,703, entitled “FlexEngine 1503,” filed on Feb. 29, 2000; U.S. Provisional PatentApplication Ser. No. 60/229,338 entitled “Flex Engine 610,” filed Sep.1, 2000; U.S. Non-Provisional Patent Application Ser. No. 09/794,219,entitled “Four Stroke Engine with Cooling System,” filed on Feb. 28,2001; U.S. Non-Provisional Patent Application Ser. No. 09/794,240,entitled “Four Stroke Engine with Valve Train Arrangement,” filed onFeb. 28, 2001; U.S. Non-Provisional Patent Application Ser. No.09/794,237, entitled “Four Stroke Engine With Intake Manifold,” filed onFeb. 28, 2001; U.S. Non-Provisional Patent Application Ser. No.09/794,218, entitled “Four Stroke Engine Having a Supercharger,” filedon Feb. 28, 2001; U.S. Non-Provisional Patent Application Ser. No.09/794,215, entitled “Four Stroke Engine Having Blow-By VentilationSystem and Lubrication System,” filed on Feb. 28, 2001; U.S.Non-Provisional Patent Application Ser. No. 09/794,238; entitled “FourStroke Engine Having Power Take Off Assembly,” filed on Feb. 28, 2001;U.S. Non-Provisional Patent Application Ser. No. 09/794,245, entitled“Four Stroke Engine Having Flexible Arrangement,” filed on Feb. 28,2001; U.S. Non-Provisional Patent Application Ser. No. 09/794,239,entitled “Control Tensioner Device For An Engine,” filed on Feb. 28,2001; U.S. Provisional Patent Application Ser. No. 60/316,207, entitled“Component Arrangement For An All Terrain Vehicle,” filed on Aug. 31,2001; U.S. Provisional Patent Application Ser. No. 60/316,029, entitled“Blow-By Gas Separator For An Internal Combustion Engine,” filed on Aug.31, 2001; U.S. Provisional Patent Application Ser. No. 60/316,030,entitled “Continuously Variable Transmission For an Internal CombustionEngine,” filed on Aug. 31, 2001; U.S. Non-Provisional Ser. No.09/944,144, entitled “Blow-By Gas Separator and Decompressor For AnInternal Combustion Engine,” filed on Sep. 4, 2001; U.S. Non-ProvisionalPatent Application Ser. No. 09/944,159, entitled “Continuously VariableTransmission For an Internal Combustion Engine,” filed on Sep. 4, 2001;and U.S. Non-Provisional Patent Application Ser. No. 09/943,737,entitled “Component Arrangement For An All Terrain Vehicle,” filed onSep. 4, 2001; all of which are assigned to the same assignee as thepresent application.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The present invention relates to a modular engine design for afamily of internal combustion engines and particularly, to a family offour-stroke engines.

[0005] 2. Description of the Related Art

[0006] In developing a new engine, significant resources go intodesigning a basic cylinder package. In an overhead valve (“OHV”)four-stroke engine, the basic cylinder package includes the cylinderitself, the cylinder head, valve train, piston, connecting rod andrelated components. These components must be designed to provide thedesired engine displacement, performance, durability, size and weight atan acceptable manufacturing cost. Therefore, in a multiple cylinderengine, some or all of these components are designed for one cylinderand are then utilized in the other cylinders in the multiple cylinderengine. For instance, it is common in an automotive engine for thepistons, connecting rods, intake valve mechanisms and exhaust valvemechanisms to be identical from cylinder to cylinder within the 4, 5, 6and 8 cylinders of that engine.

[0007] However, such a common parts package is not known in theautomotive field to have been adopted by manufacturers in a family ofengines of different basic configurations. For instance, in theautomotive field it is not known to use the common parts package in botha V-8 engine and an inline four or six cylinder engine. When amanufacturer offers, for example, both a V-8 engine and an inline (orstraight) six, each of these engines is typically independentlydeveloped from the ground up, with little parts interchangeability. Thisincreases not only the designing cost but also the cost ofmanufacturing, storing and distributing this greater number of unlikecomponents.

[0008] The use of common cylinder package components in different engineconfigurations has been previously accomplished in the motorcycle field.In the 1950's, the Vincent motorcycle company manufactured the Rapide, a1000 cc OHV V-twin, and the Meteor, a 500 cc OHV single. The Meteor usedthe same cylinder, piston, piston rings, piston pin and connecting rodas used in both cylinders of the Rapide. The Meteor also used the samecylinder head as was used on the front cylinder of the Rapide, althoughthe rear cylinder head on the Rapide differed from the front cylinderhead. The valve trains were the same on the single cylinder of theMeteor and both cylinders of the Rapide, but for the camshafts. TheMeteor camshaft was the same as the rear camshaft of the Rapide, whilethe rear camshaft of the Rapide differed from the front camshaft of theRapide. Thus, even though there was some commonality of top endcomponents between the single and the V-twin, overall commonality wasnot achieved on all cylinders of these engines as evidenced, forexample, by the different cylinder heads installed on the front and rearcylinders of the V-twin. Further, there was no use of the commoncylinder package on any other configuration of engine. Rather, theV-twin was basically the single configuration with an added cylinder.

[0009] Further, even when there has been commonality of componentswithin different engines, those engines were all intended for similaruse applications. For instance, even though the Vincent Rapide andMeteor motorcycles used common components in their respective engines,both engines were intended specifically for use in motorcycles and weresubjected to the same or very similar operating environments. Likewise,even where an automobile manufacturer has used common components invarious engines, such engines have been intended for the sameapplication, i.e., powering an automobile or truck. Consideration hasnot been given to designing common components for a plurality of enginesintended for quite diverse applications, such as for use in watercraft,boats (both inboard and outboard applications), snowmobiles, ATVs andmotorcycles, all of which place different demands on their respectiveengines.

SUMMARY OF THE INVENTION

[0010] The present invention is directed to a family of engines and amethod for designing the family of engines where each of the cylindersof each of the engines utilizes the same top end component package. Inone alternative, each of the engines of the family are overhead valve,four-stroke engines. The top end component package includes 1) at leastone exhaust valve, valve seat, valve guide, valve stem seal, valvespring, valve spring retainer and exhaust valve rocker arm; 2) at leastone intake valve, valve seat, valve guide, valve stem seal, valvespring, valve spring retainer and intake valve rocker arm. In a morecomplete approach, the top end component package can include one or moreof the following: a piston, a connecting rod, a piston pin, a small endrod bearing, a big end rod bearing, a set of piston rings, a pair ofconnecting rod bolts, a cam chain tensioner, an exhaust valve hydraulictappet for each exhaust valve, an intake valve hydraulic tappet for eachintake valve, a cylinder head and one or more camshafts (e.g., singleoverhead cam, “SOHC,” or dual overhead cam, “DOHC”). In still anotherapproach, the top end component package can include at least one rockerarm shaft.

[0011] In this way, a single basic top end component package can bedesigned once and then utilized for every cylinder of each engine in thefamily. Therefore, additional resources need not be expended indesigning new top end component packages specifically for each engine inthe family. In the most complete approach, the top end component packagecan include everything from the base gasket up. Each cylinder/head unitof each engine is identical. Alternatively, the top end componentpackage can be designed around the entire cylinder/head unit but onlyactually include certain of the moving components identified above. Inthis way, a multiple cylinder engine, such as an inline three, isdesigned with each of the cylinders based on the entire commoncylinder/head unit. Therefore, the bore, stroke and most otherdimensions are the same, as well as several of the moving componentsidentified above. However, the engine need not be required to use threeindividual cylinders, cylinder heads and camshafts. Rather, a singlecylinder block having three cylinders can be utilized, along with, ifdesired, a single cylinder head having the three combustion chambers andrelated valve trains and a single camshaft having three sets of lobesfor the three cylinders. Thus, in such an embodiment, the benefits of asingle top end component package design can be obtained without beinglimited to the use of individual cylinder/cylinder head units where suchis not desired.

[0012] In a basic embodiment of the invention, the family of enginesincludes a single cylinder engine and a V-twin, with the V-twinpreferably using two of the single cylinder engines completecylinder/cylinder head units from the base gasket up. In a furtherdevelopment of such an embodiment, the family of engines includes aninline three. However, the inline three can include three separatecomplete cylinder/cylinder head units from the base gasket up or can usethe single cylinder, cylinder head and camshaft approach discussedabove. The engine family can include further configurations, such asopposed (flat or boxer style), square (having two interconnectedcrankshafts), w-type, radial and other known configurations. Morespecifically, the engine family can include a V-four, V-six, V-eight,inline twin, inline four, opposed two and four, square four, and otherconfigurations having from 2-16 cylinders. Although use of more than 16cylinders is contemplated, it is not expected. If a 500 cc singlecylinder design is utilized, the V-twin will displace 1000 cc and theinline three will displace 1500 cc. If a 650 cc single cylinder designis utilized, the V-twin will displace 1300 cc and the inline three willdisplace 1950 cc.

[0013] In a further aspect of the invention, each of the commoncomponents between the engines of the family is designed to the standardof the strictest requirement of any of the engines. That is, where oneengine application has specific performance requirements for certain ofthe expected common components that are stricter than in other engineapplications, the common component is designed to the stricteststandard. For example, an engine for use in a marine environment canhave specific requirements for component materials and coatings toprevent corrosion. Thus, since the marine application may require that acertain component be made of a certain material and/or have a certaincoating to combat corrosion, all of these certain components for useacross the entire engine family are made to this standard, even thoughsuch corrosion resistance may not be required in other applications ofthe engine family. While this can increase certain aspects of themanufacturing cost of these components, it is expected that overall,there will be a cost savings by utilizing such an approach.

[0014] As another example, the family of engines can include bothnormally aspirated and supercharged models and/or engines intended foroperation within lower or higher RPM limits. Thus, the common componentsare designed to the stricter requirements of the supercharged engineand/or the higher RPM limit. Additionally, certain of the commoncomponents, such as connecting rods, pistons and bearings are designedto have the increased strength required in such applications. Further,since the higher RPM limit engine must be able to flow increasedquantities of air at the higher RPMs, the intake and exhaust systems aredesigned for this higher breathing requirement, even though otherengines in the family operating at lower RPMs will not need suchbreathing capability.

[0015] The added cost for such commonality at a higher level ofperformance is offset by several things. First, since the basic designfor the cylinder package is the same across the entire family, initialdesign costs are reduced since a different cylinder package design isnot required for each engine. This savings can be significant at theearly design stage and can also significantly reduce the time requiredbetween start of the design and being able to bring the final productonto the market. Second, by using the same component across the entirefamily of engines, the quantity of this component needed increases, asopposed to using different designs of this component in differentapplications. Thus, this increased number required of the same componentcan result in manufacturing efficiencies and provide volume discounts.Also, the smaller number of distinct parts will decrease the extent andcost of the tooling required for manufacturing the common components ascompared to a larger number of distinct parts.

[0016] Further, stocking and distribution costs can be decreased sinceonly the one component need be supplied to satisfy the need across theentire engine family, as opposed to having to inventory and supplymultiple different embodiments of this same component. This can beespecially beneficial when later supplying spare parts (spares) for theengines. A smaller number of unique part numbers will provide thenecessary spares support required by the entire engine family. Also,with such commonality of components, the consumer is provided additionalsources of spares for his or her application since the spares can beobtained from any dealer supplying spares for any of the engineapplications, even if the dealer is operating in a different applicationthan the consumer's. For instance, where one or more of the family ofengines is used in both snowmobiles and personal watercraft, asnowmobile consumer can obtain the common component from a personalwatercraft dealer, even though that dealer may not deal in snowmobiles.Thus, even though there can be an increased expense element associatedwith manufacturing all common components to the highest requiredstandard, the associated cost savings from decreased design time,increased manufacturing quantities and decreased inventory and supplycosts can offset this expense element and result in a net overallsavings to the company.

[0017] These savings are particularly beneficial in the design,development, manufacture, sale, and service of recreational productssuch as snowmobiles, all terrain vehicles, go carts, personalwatercraft, boats with outboard motors, boats with inboard engines,motorcycles, scooters, and light aircraft, to list the most commonmembers of the recreational vehicle family. The reason for this is asfollows. Recreational products have a production volume that isgenerally less than the production volume for automobiles. Sinceautomobiles are produced in high numbers, the costs associated withproduction and service of the vehicles and the storage of replacementparts are less pronounced. For a variety of types of recreationalvehicles, however, where the production volume is smaller, the costbenefits are more readily appreciated.

[0018] Still further aspects of the present invention will be madeapparent from the description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The figures appended hereto illustrate various aspects of thepresent invention. Where appropriate, like reference numbers refer tolike structures in the drawings, in which:

[0020]FIG. 1 is a partial phantom perspective view of a cylindercomponent package of the present invention;

[0021]FIG. 2 is a partial phantom perspective view of an inline threecylinder engine using the cylinder component package of the presentinvention;

[0022]FIG. 3 is a partial phantom view of the engine of FIG. 2, alsoshowing portions of the cylinder and cylinder head;

[0023]FIG. 4 is a perspective view of a first embodiment of a singlecylinder engine using the cylinder component package of the presentinvention;

[0024]FIG. 5 is a perspective view of a V-twin engine using two of thecylinder component packages of the present invention;

[0025]FIG. 6 is a perspective view of a second embodiment of a singlecylinder engine using the cylinder component package of the presentinvention;

[0026]FIG. 7 is a perspective view of an inline two cylinder engineusing two of the cylinder component packages of the present invention;

[0027]FIG. 8 is a perspective view of the inline three cylinder engineof FIG. 2;

[0028]FIG. 9 is a perspective view of a supercharged version of theinline three cylinder engine of FIG. 8; and

[0029]FIG. 10 is a perspective view of a V-6 engine using six of thecylinder component packages of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0030] A top end package for a single cylinder is shown generallyschematically at 10 in FIG. 1. Piston 12 is connected to connecting rod14 by piston pin (not shown) with an upper end bearing (not shown)therebetween. The piston pin is maintained in piston 12 by a pair ofretainers (not shown). A pair of bolts 20 attach connecting rod cap 22to the connecting rod 14. The connecting rod 14 mounts to a rod journal(not shown) of a crankshaft (not shown) with a lower end bearing (notshown) mounted therebetween. A set of piston rings (not shown) isinstalled on piston 12.

[0031] A lower cam drive gear (not shown) is mounted to the crankshaft(not shown) to drive cam chain 32 (illustrated as a dotted line forsimplicity) which in turn drives upper cam drive gear 34 mounted to cam36. A cam chain guide rail 38 maintains the positioning of the cam chain32. A cam chain tensioner, shown generally at 40 adjusts the slack inthe cam chain 32. A pair of intake valves 42 are mounted in intake valveguides 44 installed in a cylinder head 46 (see FIG. 3) and seal againstintake valve seats on the interior surface of the valve guides 44,respectively. Similarly, exhaust valves 50 are mounted in exhaust valveguides 52 installed in the cylinder head and seal against exhaust valveseats on the interior surface of the exhaust valve guides 52. Each valveis maintained in a closed position by a spring assembly 54 incorporatingat least one return spring, a spring retainer and a keeper. A rocker armshaft 62 is mounted in the cylinder head above the cam 36. A pair ofintake rocker arms 64 are pivotally mounted on the rocker arm shaft 62to open the intake valves 42, respectively, by action of the cam 36. Anexhaust rocker arm 66 is pivotally mounted on the rocker arm shaft 62. Asingle exhaust lobe on the cam 36 drives the exhaust rocker arm 66 thatis split on the valve side to drive both exhaust valves 50. Hydraulictappets are mounted between the rocker arms and the valves to adjust theclearance therebetween. Further details regarding these components canbe found in the U.S. Provisional and Non-Provisional patent applicationsincorporated herein by reference.

[0032] The preferred embodiment of the present invention incorporates asingle cam 36 to activate the intake valves 42 and the exhaust valves50. This is often referred to as a single overhead cam (or “SOHC”)design. While the SOHC design is preferred because it requires fewercomponents and, therefore, occupies a smaller volume, a dual overheadcam (or “DOHC”) may also be used to practice the present invention. ADOHC design provides a separate cam for each of the intake and exhaustvalves 42, 50.

[0033] The common top end package can include some or all of thesecomponents and can further include components such as the cylinder andcylinder head, assorted gaskets, seals, bearings, fasteners and covers,among other things. Thus, the complete cylinder design, including intakeand exhaust port shapes, combustion chamber design and most of the otherfactors that go into the single cylinder design can be utilized in othercylinders of engines of the engine family.

[0034] The common top end package is also designed so that it will becapable of providing at least the minimum performance necessary toaccommodate the most stringent requirements of any of the engines in theengine family. For instance, an engine of the engine family intended foruse in a small watercraft may require a relatively flat torque curvematched to the torque curve required to drive the watercraft propelleror jet pump impeller. Further, the engine will not require exceedinglyhigh RPM operation and may have a rev limit of about 7500 RPM.Therefore, the basic engine design must be capable of such operation. Onthe other hand, an engine intended for a motorcycle will likely requirehigher RPM operation than the watercraft engine to address the needs ofthe motorcycle market. This higher RPM operation, for instance, to10,000 RPM or higher, will require that the intake and exhaust systemshave the ability to adequately flow at the higher RPM. It will alsorequire that each of the moving engine components be able to withstandthe higher velocities, accelerations and forces associated with thehigher RPM. Thus, for instance, the rods and pistons must be designed towithstand the higher loading due to the higher RPM and the valve trainmust not float at such RPM.

[0035] For a family of engines that is intended to power a diverse lineof recreational vehicles, such as personal watercraft, boats (includinginboard and outboard engines), snowmobiles, ATVs and motorcycles, thereare a number of most demanding requirements that are applied to theengine family as a result of the specific requirements imposed by eachof the vehicles. For instance, since a snowmobile operates in coldweather conditions, it is important to design the engine so that it canstart and run without damage at −40° C. This may include designing theengine to use a decompression device for starting to reduce the torquerequired from either a manual or electric starter to start the engine.Furthermore, the oil and cooling systems must be designed to operate atsuch low temperatures until the engine has warmed up. This applicationis also very sensitive to engine weight, especially as compared totwo-stroke engines, so it is important to obtain high performance fromthe engine for the given engine weight. In this regard, the engine isable to be turbocharged to increase engine performance. Since the enginemust turn at a relatively high RPM above idle before the CVT starts toengage, turbocharger boost starts before such CVT engagement andturbocharger lag is minimized or eliminated. On the other hand, thisengine needs to deliver full power without resorting to high RPM, sincesuch high RPM substantially increases the wear of the CVT belt.

[0036] A watercraft application, for example, a small boat or personalwatercraft, has other requirements. Since the watercraft operates in amarine environment, the engine must be corrosion resistant, especiallywhen operating in salt water. Here, performance is also important, butthe engine torque curve must be tailored to match the torque curverequirement of the propeller or jet pump impeller. A turbocharged enginedoes not work well in such an application because the torque curve fromsuch an engine does not match the torque curve requirement of thepropeller or jet pump impeller. On the other hand, a superchargedengine, i.e., an engine with a positively driven supercharger, asopposed to an exhaust gas driven turbocharger, can provide higherperformance and works well in such an application since the torquesupplied curve closely matches the torque required curve. While such asupercharged engine may not produce the same peak power as aturbocharged engine, the performance increase is welcome and relativelyinexpensive, especially when using a positively driven vane impellersupercharger. However, such a supercharger does not work particularlywell in a land-based vehicle that has a positive drive connection withthe ground. As with the snowmobile application, this engine needs todeliver full power without resorting to high RPM because the propelleror impeller loses efficiency at such high RPM.

[0037] Furthermore, the crankshaft for this application must be of asufficient size and diameter so as to handle the requirements of thePTO, the generator and other accessories driven by the crankshaft in atypical watercraft installation. However, a large diameter crankshaftresults in a large diameter timing chain drive gear. The large diametercrank gear means a larger driven cam gear (the cam gear is twice thesize of the drive gear if no intermediate gear is used) and results in alarger head. However, it is desirable across the entire engine family tohave a compact head design because this reduces the amount of spacenecessary to accommodate a given engine in a specific vehicle. In thepresent invention, the head has been designed to have a single camshaft62 disposed between the narrow angle of the valves to reduce the overallsize of the head.

[0038] An ATV, in many applications, does not require the highperformance of the other vehicles mentioned. For instance, torque outputcan be lower, as well as peak RPM. However, the engine must start easilyacross a wide temperature range. Therefore, the engine should be able toeasily adopt a decompression device for easing starting, especially onengines having only a manual starter.

[0039] A motorcycle has very different power output requirements thanthe vehicles above. In most applications, the engine must provide highperformance and be able to operate at the highest RPM of any of thevehicles identified herein. However, the engine must be able to pullstrongly from idle, since the motorcycle uses a gearbox and not a CVT.Therefore, the engine must be capable of high performance in a normallyaspirated state since turbo lag is generally unacceptable.

[0040] Therefore, when designing the top end package for an enginefamily that will provide engines to such diverse vehicles, it isimportant to design the package to accommodate each of the strictestrequirements discussed above. Thus, depending on the power requirements,the same basic package must be capable of being normally aspirated,turbocharged and/or supercharged, as well as being capable of both lowand high RPM operation. It must be readily tuned to best match theoutput torque with the application and must be readily started andoperable across a broad temperature range. It is important to keep theoverall size of the package small so that each engine can be most easilyaccommodated within the available space of the vehicle.

[0041]FIG. 2 shows how the identical components described above withrespect to a single cylinder application are used with respect to eachcylinder of a three cylinder inline engine of the family (with theexception of the cam, which is extended to handle all cylinders). FIG. 3shows a downward perspective view of the components shown in FIG. 2. Inthis embodiment, it is contemplated that a single cylinder block and asingle cylinder head be used, as opposed to three separate cylinders andheads. Alternatively, the separate cylinders and heads can be utilized.Although not shown here, the crankshaft is different from the crankshaftused in the single cylinder engine as it will have three rod journals(among other things) as opposed to one rod journal.

[0042] The same basic cylinder design can also be used to providedifferent cylinder capacities, and thus different engine capacities,merely by changing the stroke of the crankshaft. Generally, this willalso involve changing the length of the connecting rod, as is known.Therefore, the same single cylinder design having a bore of 100 mm canprovide a cylinder displacement of 498 cc when utilized in conjunctionwith a crankshaft having a stroke of 63.4 mm and a cylinder displacementof 644 cc when utilized in conjunction with a crankshaft having a strokeof 82 mm. Only the crankshaft, the connecting rod and the length of thetiming chain need be changed to do so, the cylinder and other componentscan be the same in both instances. Other bores and strokes are alsopossible depending on the desired characteristics of the cylinderdesign.

[0043] Thus, the same basic cylinder design can be used with a commontop end component package to create a family of engines especiallyadapted to different applications. For instance, a single cylinderengine of between 400-650 cc (generally) can be used in an ATV ormotorcycle. A V-twin or inline twin of between 1000-1300 cc (generally)can be used in an ATV, motorcycle, snowmobile or personal watercraft. Aninline three or four cylinder of between 1500-2600 cc (generally) can beused in a motorcycle, snowmobile, personal watercraft or small boat(both inboard and outboard applications). A V-six engine of between3000-3900 cc (generally) can be used in a boat. Other sizes andconfigurations can be used in other applications, such as automobiles,industrial vehicles and aircraft, as the applications require. All ofthis is based on one cylinder design.

[0044]FIG. 4 shows a general schematic view of a single cylinder engine100 according to the present invention. In the configuration shown, theengine is normally aspirated. However, in this and all of the otherconfigurations, the engines can either be normally aspirated orsupercharged and can use either one or more carburetors or some form offuel injection.

[0045]FIG. 5 shows a general schematic view of a V-twin engine 110according to the present invention. Here, the same top end package asused in the single cylinder engine 100 is used in both cylinders of theV-twin. The same cylinder and cylinder heads are used, although in thisconfiguration, the rear cylinder and cylinder head have been rotated180° so that intake ports of each cylinder can be positioned facing oneanother for convenience of intake plumbing. In such an embodiment, therotation of the cylinder and cylinder head will require a rear camhaving a reverse grind and may require reversal of the cam chain guiderail and cam chain tensioner. Alternatively, the V-twin can be designedwith both cylinders having the same orientation, for instance, with bothexhaust ports facing forward. The V-twin of FIG. 5 requires a differentcrankshaft and crankcase than that of FIG. 4. However, the crankcase ofFIG. 5 can be used in a single cylinder embodiment as long as one of thecylinder openings is blocked off and a crankshaft with a rod journalappropriate for one connecting rod is used with balancing appropriatefor a single cylinder. This embodiment is particularly suited for use ina snowmobile.

[0046]FIG. 6 shows a general schematic of a second embodiment of asingle cylinder engine 112 according to the present invention. Inparticular, this engine configuration provides for a displacement ofabout 610 cc's. The details of this engine are described in several ofthe applications incorporated herein by reference, as indicated above.

[0047]FIG. 7 shows a general schematic view of an inline twin engine 120according to the present invention. Here, the same top end package asused in the single cylinder engine 100 is used in both cylinders of theinline twin. However, a single cylinder block 122 and cylinder head 124is used.

[0048]FIG. 8 shows a general schematic view of an inline three engine130 according to the present invention. Here, the same top end packageas used in the single cylinder engine 100 is used in all threecylinders. However, as with the inline twin of FIG. 6, a single cylinderblock 132 and cylinder head 134 is used. This embodiment is normallyaspirated.

[0049]FIG. 9 shows the engine of FIG. 8 but in a supercharger embodimentusing a positively driven blower. The supercharger for engine 130′ isdesignated as 135. This embodiment is particularly suited for use in awatercraft.

[0050]FIG. 10 shows a general schematic view of a V-6 engine 140according to the present invention. Here, the same top end package asused in the single cylinder engine 100 is used in all six cylinders.Further, the same cylinder head as used in the inline three engine ofFIG. 8 is used on both banks of the V but rotated, as with the V-twin ofFIG. 5. A different, unitary cylinder block 142 is used, as is adifferent crankshaft, as compared to the inline three.

[0051] The description of several embodiments of the present inventionabove is meant to illustrate the breadth of the present invention and isnot meant to limit the appended claims solely to the subject matterdescribed. To the contrary, the broad scope of the present invention isapparent from the foregoing description.

What is claimed is:
 1. A modular family of internal combustion engines,wherein: the family includes at least three engines, each with adifferent configuration selected from a group comprising singlecylinder, V-type, inline, opposed, square, w-type and radial; and eachof the engines includes at least one cylinder, each cylinder of eachengine of the family using identical top end component packages.
 2. Amodular family of internal combustion engines as in claim 1, wherein theengines are all overhead valve, four-stroke engines and the top endcomponent package comprises: at least one exhaust valve, valve seat,valve guide, valve stem seal, valve spring, valve spring retainer andexhaust valve rocker arm; and at least one intake valve, valve seat,valve guide, valve stem seal, valve spring, valve spring retainer andintake valve rocker arm.
 3. A modular family of internal combustionengines as in claim 2, wherein the top end component package furthercomprises: a piston pin; a small end rod bearing; a big end rod bearing;a set of piston rings; a pair of connecting rod bolts; a cam chaintensioner; an exhaust valve hydraulic tappet for each exhaust valve; andan intake valve hydraulic tappet for each intake valve.
 4. A modularfamily of internal combustion engines as in claim 3, wherein the top endcomponent package further comprises: a piston; and a connecting rod. 5.A modular family of internal combustion engines as in claim 4, whereinthe top end component package further comprises: a cylinder head; and acamshaft.
 6. A modular family of combustion engines as in claim 5,wherein the top end component package further comprises: at least onerocker arm shaft.
 7. A modular family of internal combustion engines asin claim 1, wherein the engine configurations comprise at least threefrom a group comprising: a single cylinder, a V-twin, and an inlinetwin, and an inline three.
 8. A modular family of internal combustionengines as in claim 7, wherein the engine configurations furthercomprise at least one from a group comprising: a V-six, a V-four and aninline four.
 9. An engine from a modular family of internal combustionengines, comprising: at least one cylinder; and a top end componentpackage associated with the at least one cylinder; wherein the familyincludes at least three engines, each with a different configurationselected from a group comprising single cylinder, V-type, inline,opposed, square, w-type and radial; and wherein each cylinder of eachengine of the family uses identical top end component packages.
 10. Anengine from a modular family of internal combustion engines as in claim9, wherein all of the engines of the family are overhead valve,four-stroke engines and the top end component package comprises: atleast one exhaust valve, valve seat, valve guide, valve stem seal, valvespring, valve spring retainer and exhaust valve rocker arm; and at leastone intake valve, valve seat, valve guide, valve stem seal, valvespring, valve spring retainer and intake valve rocker arm.
 11. An enginefrom a modular family of internal combustion engines as in claim 10,wherein the top end component package further comprises: a piston pin; asmall end rod bearing; a big end rod bearing; a set of piston rings; apair of connecting rod bolts; a cam chain tensioner; an exhaust valvehydraulic tappet for each exhaust valve; and an intake valve hydraulictappet for each intake valve.
 12. An engine from a modular family ofinternal combustion engines as in claim 11, wherein the top endcomponent package further comprises: a piston; and a connecting rod. 13.An engine from a modular family of internal combustion engines as inclaim 12, wherein the top end component package further comprises: acylinder head; and a camshaft.
 14. An engine from a modular family ofinternal combustion engines as in claim 13, wherein the top endcomponent package further comprises: at least one rocker arm shaft. 15.An engine from a modular family of internal combustion engines as inclaim 9, wherein the engine configurations comprise at least three froma group comprising: a single cylinder, a V-twin, and an inline twin, andan inline three.
 16. An engine from a modular family of internalcombustion engines as in claim 15, wherein the engine configurationsfurther comprise at least one from a group comprising: a V-six, aV-four, and an inline four.
 17. A method for manufacturing a modularfamily of internal combustion engines, comprising: designing a singletop end component package; and designing a single cylinder engine and atleast two multiple cylinder engines, each of the multiple cylinderengines having a different configuration selected from a groupcomprising V-type, inline, opposed, square, w-type and radial; whereineach cylinder of each engine of the family uses the same top endcomponent package designed in the first step.
 18. A method formanufacturing a modular family of internal combustion engines as inclaim 17, wherein all of the engines of the family are overhead valve,four-stroke engines and the step for designing the top end componentpackage includes designing the following components of the top endpackage: at least one exhaust valve, valve seat, valve guide, valve stemseal, valve spring, valve spring retainer and exhaust valve rocker arm;and at least one intake valve, valve seat, valve guide, valve stem seal,valve spring, valve spring retainer and intake valve rocker arm.
 19. Amethod for manufacturing a modular family of internal combustion enginesas in claim 18, wherein the step for designing the top end componentpackage includes designing the further following components of the topend package: a piston pin; a small end rod bearing; a big end rodbearing; a set of piston rings; a pair of connecting rod bolts; a camchain tensioner; an exhaust valve hydraulic tappet for each exhaustvalve; and an intake valve hydraulic tappet for each intake valve.
 20. Amethod for manufacturing a modular family of internal combustion enginesas in claim 19, wherein the step for designing the top end componentpackage includes designing the further following components of the topend package: a piston; and a connecting rod.
 21. A method formanufacturing a modular family of internal combustion engines as inclaim 20, wherein the step for designing the top end component packageincludes designing the further following components of the top endpackage: a cylinder head; and a camshaft.
 22. A method for manufacturinga modular family of internal combustion engines as in claim 21, whereinthe step for designing the top end component package includes designing:at least one rocker arm shaft.
 23. A method for manufacturing a modularfamily of internal combustion engines as in claim 17, wherein the stepfor designing the single cylinder engine and at least two multiplecylinder engines includes designing at least two of the following engineconfigurations: a V-twin, an inline twin, and an inline three.
 24. Amethod for manufacturing a modular family of internal combustion enginesas in claim 23, wherein the step for designing the single cylinderengine and at least two multiple cylinder engines includes furtherdesigning at least one of the following engine configurations: a V-six,a V-four, and an inline four.
 25. A method for reducing a number ofunique components required for manufacturing a modular family ofinternal combustion engines, comprising: designing a single top endcomponent package; designing a single cylinder engine and at least twomultiple cylinder engines, each of the multiple cylinder engines havinga different configuration selected from a group comprising V-type,inline, opposed, square, w-type and radial; wherein, each cylinder ofeach engine of the family uses the same top end component packagedesigned in the first step and each component in the top end componentpackage is designed to comply with the strictest performance requirementfor that component in any application utilizing one of the family ofengines.
 26. A method as in claim 25, wherein all of the engines of thefamily are overhead valve, four-stroke engines and the step fordesigning the top end component package includes designing the followingcomponents of the top end package: at least one exhaust valve, valveseat, valve guide, valve stem seal, valve spring, valve spring retainerand exhaust valve rocker arm; and at least one intake valve, valve seat,valve guide, valve stem seal, valve spring, valve spring retainer andintake valve rocker arm.
 27. A method as in claim 26, wherein the stepfor designing the top end component package includes designing thefurther following components of the top end package: a piston pin; asmall end rod bearing; a big end rod bearing; a set of piston rings; apair of connecting rod bolts; a cam chain tensioner; an exhaust valvehydraulic tappet for each exhaust valve; and an intake valve hydraulictappet for each intake valve.
 28. A method as in claim 27, wherein thestep for designing the top end component package includes designing thefurther following components of the top end package: a piston; and aconnecting rod.
 29. A method as in claim 28, wherein the step fordesigning the top end component package includes designing the furtherfollowing components of the top end package: a cylinder head; and acamshaft.
 30. A method as in claim 29, wherein the step for designingthe top end component package includes designing: at least one rockerarm shaft.
 31. A method as in claim 25, wherein the step for designingthe single cylinder engine and at least two multiple cylinder enginesincludes designing at least two of the following engine configurations:a V-twin, an inline twin, and an inline three.
 32. A method as in claim31, wherein the step for designing the single cylinder engine and atleast two multiple cylinder engines includes further designing at leastone of the following engine configurations: a V-six, a V-four, and aninline four.
 33. One from a family of recreational vehiclesincorporating one from a modular family of internal combustion engines,wherein: the family of engines includes at least two engines, each witha different configuration selected from a group comprising singlecylinder, V-type, inline, opposed, square, w-type and radial; each ofthe engines includes at least one cylinder, each cylinder of each engineof the family using identical top end component packages; and the familyof recreational vehicles encompasses at least two recreational vehiclesselected from a group comprising snowmobiles, all terrain vehicles, gocarts, personal watercraft, boats with outboard motors, boats withinboard engines, motorcycles, scooters, and light aircraft.
 34. One froma family of recreational vehicles as in claim 33, wherein the enginesare all overhead valve, four-stroke engines and the top end componentpackage comprises: at least one exhaust valve, valve seat, valve guide,valve stem seal, valve spring, valve spring retainer and exhaust valverocker arm; and at least one intake valve, valve seat, valve guide,valve stem seal, valve spring, valve spring retainer and intake valverocker arm.
 35. One from a family of recreational vehicles as in claim34, wherein the top end component package further comprises: a pistonpin; a small end rod bearing; a big end rod bearing; a set of pistonrings; a pair of connecting rod bolts; a cam chain tensioner; an exhaustvalve hydraulic tappet for each exhaust valve; and an intake valvehydraulic tappet for each intake valve.
 36. One from a family ofrecreational vehicles as in claim 35, wherein the top end componentpackage further comprises: a piston; and a connecting rod.
 37. One froma family of recreational vehicles as in claim 36, wherein the top endcomponent package further comprises: a cylinder head; and a camshaft.38. One from a family of recreational vehicles as in claim 37, whereinthe top end component package further comprises: at least one rocker armshaft.
 39. One from a family of recreational vehicles as in claim 33,wherein the engine configurations comprise at least two from a groupcomprising: a single cylinder, a V-twin, and an inline twin, and aninline three.
 40. One from a family of recreational vehicles as in claim39, wherein the engine configurations further comprise at least one froma group comprising: a V-six, a V-four and an inline four.
 41. A familyof recreational vehicles sharing a modular family of internal combustionengines, wherein: the family of engines includes at least two engines,each with a different configuration selected from a group comprisingsingle cylinder, V-type, inline, opposed, square, w-type and radial;each of the engines includes at least one cylinder, each cylinder ofeach engine of the family using identical top end component packages;and the family of recreational vehicles encompasses at least tworecreational vehicles selected from a group comprising snowmobiles, allterrain vehicles, go carts, personal watercraft, boats with outboardmotors, boats with inboard engines, motorcycles, scooters, and lightaircraft.
 42. A family of recreational vehicles as in claim 41, whereinthe engines are all overhead valve, four-stroke engines and the top endcomponent package comprises: at least one exhaust valve, valve seat,valve guide, valve stem seal, valve spring, valve spring retainer andexhaust valve rocker arm; and at least one intake valve, valve seat,valve guide, valve stem seal, valve spring, valve spring retainer andintake valve rocker arm.
 43. A family of recreational vehicles as inclaim 42, wherein the top end component package further comprises: apiston pin; a small end rod bearing; a big end rod bearing; a set ofpiston rings; a pair of connecting rod bolts; a cam chain tensioner; anexhaust valve hydraulic tappet for each exhaust valve; and an intakevalve hydraulic tappet for each intake valve.
 44. A family ofrecreational vehicles as in claim 43, wherein the top end componentpackage further comprises: a piston; and a connecting rod.
 45. A familyof recreational vehicles as in claim 44, wherein the top end componentpackage further comprises: a cylinder head; and a camshaft.
 46. A familyof recreational vehicles as in claim 45, wherein the top end componentpackage further comprises: at least one rocker arm shaft.
 47. A familyof recreational vehicles as in claim 41, wherein the engineconfigurations comprise at least two from a group comprising: a singlecylinder, a V-twin, and an inline twin, and an inline three.
 48. Afamily of recreational vehicles as in claim 47, wherein the engineconfigurations further comprise at least one from a group comprising: aV-six, a V-four and an inline four.
 49. A method for manufacturing onefrom a family of recreational vehicles sharing a family of internalcombustion engines, comprising: designing a single top end componentpackage; and designing two engines, each having a different engineconfiguration selected from a group comprising single cylinder, V-type,inline, opposed, square, w-type and radial; wherein each cylinder ofeach engine of the family uses the same top end component packagedesigned in the first step; and wherein the plurality of recreationalvehicle types encompasses at least two from a group comprisingsnowmobiles, all terrain vehicles, go carts, personal watercraft, boatswith outboard motors, boats with inboard engines, motorcycles, scooters,and light aircraft.
 50. A method for manufacturing one from a family ofrecreational vehicles as in claim 49, wherein all of the engines of thefamily are overhead valve, four-stroke engines and the step fordesigning the top end component package includes designing the followingcomponents of the top end package: at least one exhaust valve, valveseat, valve guide, valve stem seal, valve spring, valve spring retainerand exhaust valve rocker arm; and at least one intake valve, valve seat,valve guide, valve stem seal, valve spring, valve spring retainer andintake valve rocker arm.
 51. A method for manufacturing one from afamily of recreational vehicles as in claim 50, wherein the step fordesigning the top end component package includes designing the furtherfollowing components of the top end package: a piston pin; a small endrod bearing; a big end rod bearing; a set of piston rings; a pair ofconnecting rod bolts; a cam chain tensioner; an exhaust valve hydraulictappet for each exhaust valve; and an intake valve hydraulic tappet foreach intake valve.
 52. A method for manufacturing one from a family ofrecreational vehicles as in claim 51, wherein the step for designing thetop end component package includes designing the further followingcomponents of the top end package: a piston; and a connecting rod.
 53. Amethod for manufacturing one from a family of recreational vehicles asin claim 52, wherein the step for designing the top end componentpackage includes designing the further following components of the topend package: a cylinder head; and a camshaft.
 54. A method formanufacturing one from a family of recreational vehicles as in claim 53,wherein the step for designing the top end component package includesdesigning: at least one rocker arm shaft.
 55. A method for manufacturingone from a family of recreational vehicles as in claim 49, wherein thestep for designing the single cylinder engine and at least two multiplecylinder engines includes designing at least one of the following engineconfigurations: a V-twin, an inline twin, and an inline three.
 56. Amethod for manufacturing one from a family of recreational vehicles asin claim 55, wherein the step for designing the single cylinder engineand at least two multiple cylinder engines includes further designing atleast one of the following engine configurations: a V-six, a V-four, andan inline four.
 57. A method for manufacturing a family of recreationalvehicles sharing a family of internal combustion engines, comprising:designing a single top end component package; and designing two engines,each having a different engine configuration selected from a groupcomprising single cylinder, V-type, inline, opposed, square, w-type andradial; wherein each cylinder of each engine of the family uses the sametop end component package designed in the first step; and wherein theplurality of recreational vehicle types encompasses at least two from agroup comprising snowmobiles, all terrain vehicles, go carts, personalwatercraft, boats with outboard motors, boats with inboard engines,motorcycles, scooters, and light aircraft.
 58. A method formanufacturing a family of recreational vehicles as in claim 57, whereinall of the engines of the family are overhead valve, four-stroke enginesand the step for designing the top end component package includesdesigning the following components of the top end package: at least oneexhaust valve, valve seat, valve guide, valve stem seal, valve spring,valve spring retainer and exhaust valve rocker aim; and at least oneintake valve, valve seat, valve guide, valve stem seal, valve spring,valve spring retainer and intake valve rocker arm.
 59. A method formanufacturing a family of recreational vehicles as in claim 58, whereinthe step for designing the top end component package includes designingthe further following components of the top end package: a piston pin; asmall end rod bearing; a big end rod bearing; a set of piston rings; apair of connecting rod bolts; a cam chain tensioner; an exhaust valvehydraulic tappet for each exhaust valve; and an intake valve hydraulictappet for each intake valve.
 60. A method for manufacturing a family ofrecreational vehicles as in claim 59, wherein the step for designing thetop end component package includes designing the further followingcomponents of the top end package: a piston; and a connecting rod.
 61. Amethod for manufacturing a family of recreational vehicles as in claim60, wherein the step for designing the top end component packageincludes designing the further following components of the top endpackage: a cylinder head; and a camshaft.
 62. A method for manufacturinga family of recreational vehicles as in claim 61, wherein the step fordesigning the top end component package includes designing: at least onerocker arm shaft.
 63. A method for manufacturing a family ofrecreational vehicles as in claim 57, wherein the step for designing thesingle cylinder engine and at least two multiple cylinder enginesincludes designing at least one of the following engine configurations:a V-twin, an inline twin, and an inline three.
 64. A method formanufacturing a family of recreational vehicles as in claim 63, whereinthe step for designing the single cylinder engine and at least twomultiple cylinder engines includes further designing at least one of thefollowing engine configurations: a V-six, a V-four, and an inline four.65. A method for reducing a number of unique components required formanufacturing a family of recreational vehicles sharing a family ofinternal combustion engines, comprising: designing a single top endcomponent package; and designing a single cylinder engine and at leastone multiple cylinder engine with a configuration selected from a groupcomprising V-type, inline, opposed, square, w-type and radial; whereineach cylinder of each engine of the family uses the same top endcomponent package designed in the first step and each component in thetop end component package is designed to comply with the strictestperformance requirement for that component in any application utilizingone of the family of engines; and wherein the plurality of recreationalvehicle types encompasses at least two from a group comprisingsnowmobiles, all terrain vehicles, go carts, personal watercraft, boatswith outboard motors, boats with inboard engines, motorcycles, scooters,and light aircraft.
 66. A method as in claim 65, wherein all of theengines of the family are overhead valve, four-stroke engines and thestep for designing the top end component package includes designing thefollowing components of the top end package: at least one exhaust valve,valve seat, valve guide, valve stem seal, valve spring, valve springretainer and exhaust valve rocker arm; and at least one intake valve,valve seat, valve guide, valve stem seal, valve spring, valve springretainer and intake valve rocker arm.
 67. A method as in claim 66,wherein the step for designing the top end component package includesdesigning the further following components of the top end package: apiston pin; a small end rod bearing; a big end rod bearing; a set ofpiston rings; a pair of connecting rod bolts; a cam chain tensioner; anexhaust valve hydraulic tappet for each exhaust valve; and an intakevalve hydraulic tappet for each intake valve.
 68. A method as in claim67, wherein the step for designing the top end component packageincludes designing the further following components of the top endpackage: a piston; and a connecting rod.
 69. A method as in claim 68,wherein the step for designing the top end component package includesdesigning the further following components of the top end package: acylinder head; and a camshaft.
 70. A method as in claim 69, wherein thestep for designing the top end component package includes designing: atleast one rocker arm shaft.
 71. A method as in claim 65, wherein thestep for designing the single cylinder engine and at least two multiplecylinder engines includes designing at least one of the following engineconfigurations: a V-twin, an inline twin, and an inline three.
 72. Amethod as in claim 71, wherein the step for designing the singlecylinder engine and at least two multiple cylinder engines includesfurther designing at least one of the following engine configurations: aV-six, a V-four, and an inline four.